St Mirren left Dingwall empty-handed after a late Jordan White header consigned Saints to a 1-0 defeat.
Stephen Robinson made three changes to the starting eleven that defeated Livingston 1-0 at The SMiSA Stadium on Saturday. Richard Taylor missed out after coming off with an ankle injury and was replaced by Charles Dunne. Keanu Baccus returned from suspension in place of Caolan Boyd-Munce, while Alex Greive started ahead of Jonah Ayunga who played 60 minutes on his return at the weekend.
White had the game's first opportunity with a strike from the edge of the area into the arms of Zach Hemming on four minutes. The goalkeeper started a quick counter that saw Greg Kiltie deliver a dangerous looking low ball across from the left, but the County defence managed to clear.
After a scrappy opening half-hour, Saints started to assert themselves more before the break. A terrific ball in from Scott Tanser looked like it might fall for Greive, but he was quickly challenged by a County defender as he looked to pull the trigger.
The Buddies best chance of the half came on 38 minutes when Alex Gogic rose the highest to meet a Kiltie corner at the back post. The Cypriot international wasn't far away from the opener but sent the header into the side net with the first-half ending goalless.
There was a VAR check for a St Mirren penalty five minutes after the restart when Conor McMenamin went down under a challenge inside the box. But nothing was awarded.
The hosts came close to opening the scoring on 55 minutes with their best effort of the match. White teed the ball off for Connor Randall who took a touch before cracking an effort off the post from the edge of the area. The County man should have opened the scoring on the hour mark when he was the recipient of a fortunate break of the ball that allowed him to run clear on goal. He got the effort all wrong though as he fired well over.
Saints made their first change of the game immediately after with Ayunga coming on to replace Mandron while Stav Nahmani was introduced 12 minutes later in place of Greive.
The home side were denied by a brilliant Zach Hemming save with 12 minutes remaining. White's flick-on saw Simon Murray race into the box. The forward pulled the ball across the area to Ben Purrington who looked to tuck it into the corner of the net but saw his attempt beaten away by the Saints stopper. McMenamin had Saints' best chance of the second-half a few moments when his curling effort from the edge of the box was pushed away by Ross Laidlaw.
Ross County took the lead with a little over five minutes of the match remaining. White rose the highest to bullet home a header from a corner which would ultimately prove enough for the home side to take the points.
Full-Time: Ross County 1-0 St Mirren
St Mirren: Hemming, Fraser, Gogic, Dunne, McMenamin, Baccus (Boyd-Munce 82), O'Hara (c), Kiltie (Flynn 82), Tanser, Mandron (Ayunga 60), Greive (Nahmani 72)
Subs Not Used: Urminsky, Bolton, Small, Jamieson, Olusanya
Ross County: Laidlaw, Nightingale, Baldwin, Leak, Brown, Allardice, Randall, Purrington, Dhanda (Turner 74), Murray (Samuel 83), White
Subs Not Used: Munro, Sheaf, Loturi, Harmon, Smith, Reid
Referee: William Collum
Assistant Referee: Gordon McCabe
Assistant Referee: Graham McNeillie
Fourth Official: George Calder
VAR: Kevin Clancy
Attendance: 3758 (265 saints)
